mcclellan



E. L McCLELLAN.

CHUCK.

APPLICATION FILED AUG-I7. 1917.

Patented May 27, 1919.

2 SHEETS-SHEET l.

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E. J. McGLELLAN.

CHUCK.

APPLICATION FILED AUG-l7, $917.

1 1 3', Patented May 27, 1919.

2 SHEETS-SHEET 2.

M ATTORNEYS TTNTTED @TAT FATENT @FFT@E.

EDWARD J. MGCLELLAN, OF NEW YORK, N. Y., ASSIGNOR TO THE GARVIN MACHINE 00., A CORPORATION OF NEW YORK.

CHUCK.

Specification of Letters Patent.

Patented May 2'7, 191?).

To all whom it may concern:

Be it known that I, EDWARD J. MOCLELLAN, a citizen of the United States, residing at the city of New York, in the borough of Manhattan and State of New York, have invented certain new and useful Improvements in Chucks, of which the following is a full, clear, and exact description.

This invention relates to lathe-chucks of the type in which the jaws of a chuck are actuated by a common member which has inclined surfaces in sliding engagement with correspondingly inclined surfaces on the jaws whereby a linear reciprocation of the common member will cause a simultaneous radial movement of the jaws.

One object of the invention is to provide the common member and jaws with engaging parts which are so constructed that a central pull will be exerted on each of the jaws to move it toward its closed position; or in other words, the direction of the pull will be parallel to the longitudinal axis of the jaw.

Other objects of the invention are to provide engaging parts which will remain in firm contact during the actuation of the jaws, will not be subject to undue wear and which will be of sufficient strength to sustain the stresses to which these parts are subjected when the work is gripped in the chuck.

With these and other objects in view, the invention consists of a common member or block having a plurality of axially directed T-shaped recesses and actuating jaws with longitudinal extensions from their lower ends of a shape to fit into the T-shaped grooves and to slide therein, the surfaces of the extensions from the jaws and the T- shaped grooves having their contacting surfaces inclined to the horizontal whereby a linear reciprocation of the common member will cause a radial movement of the jaws.

The invention also consists of the constructions and combinations hereinafter set forth in the detailed description in conjunction with the accompanying drawings and pointed out in the appended claims.

In the drawings:

Figure 1 is a front view of the chuck constructed in accordance with the principles of the invention;

Fig. 2 is a top view thereof;

Fig. 3 is a central vertical section;

Fig. 4 is a front elevation of one of the actuating jaws;

Fig. 5 is a detail showing in perspective the actuating wedge or block;

Fig. 6 is a detail showing in perspective one of the actuating jaws; and

Fig. 7 is a detail showing in perspective one of the false jaws.

The head of the chuck, which is indicated 1, is similar to chucks of this character, and consists of an annulus or ring to the rear face of which is secured a face plate 2 which may be threaded as at 2 to secure it in place upon the threaded nose of a lathe-spindle. The face plate may be of any suitable shape and one type of face plate is shown in Fig. 3 which is secured to the head 1 by means of bolts 3; in Fig. 2 a slightly modified form of face plate is shown. The front face of the head 1 is provided with a plurality of rectangular recesses, which recesses are radially disposed and are adapted to receive the rec tangularly-shaped actuating jaws 4, the recesses preferably being provided with guides or ways 5 upon which the jaws slide. Each of the jaws 4 has a central vertical recess or groove 7 cut in its front face. False jaws 8 which are adapted to grip the work are each provided with a ridge or projection 9 which fits into the recess 7 similar to a mortise joint. The front face of the actuating jaw, as well as the rear face of the false jaws 8, are also provided with a horizontal recess into which a block or key 10 fits, which block is held in place by a screw 10. The false jaws are secured to the actuating jaws by bolts 11, this part of the construction being common to chucks of this character.

The wedge or block for actuating the jaws comprises a cylindrical block 12 which has axially-directed T-shaped grooves 13 cut in its periphery in each of which grooves a T- sh-aped extension 14 on one of the actuating jaws 4: is adapted to slide. As will be clear from Fig. 5, the walls of the T-shaped slots are inclined to the axis of the block and the engaging walls of the T-shaped extension 1a are correspondingly inclined so that a linear reciprocation of the block 12 within the head will cause a radial movement of the actuating jaws. The cylindrical block 12 is preferably of a size to have a sliding fit in the central opening through the head 1, as is clear from Fig. 3, and the block is also provided with a central opening in which is mounted a boring bar bushing 17. The rear end of the central opening through the block 12 is threaded as at 18 to which is secured a draw-bar or tube 19 for reciprocating the block, it being understood that this bar extends through the hollow spindle of the lathe and is connected to the usual means for operating it. The front face of the chuck is covered by a guard or protector plate 20, which fits into a recess in the front face and is flush therewith. This plate rests against the actuating jaws, and is provided with radial slots 21, thefalse' jaws 8 being recessed as at 22 to fitaround the slots 21 and to hold the plate against movement.

The manner in which the chuck operates is obvious from the previous description; 2'. 6., a linear reciprocationof the block 12 within the chuck head will cause a radial movement of the jaws either to their opened or closed position, depending upon-the direction of movement of the block. lVhen the jaws are moved inwardly to their closed position, the .upper surfaces of both legs of the T-shaped extension 14 of an actuating jaw will bear, against the corresponding walls of one of the 'T-shaped grooves 13 within the block 12, and serve as wedges or teeth to cause the jaws tomove, and since the legs of the T-shaped extensions are disposed upon each side of the longitudinal axis of the jaws, the pull exerted bythe block to cause each of the jaws to grip the work will be a central pull; 2'. 6., one parallel to the longitudinal axis of the jaw which'will cause the jaws to grip the work firmly without any tendency'for a side thrust upon the aws.

It will also be apparent that with a T- shaped engaging part on each of the actuating jaws, the two arms formingthe top of the T will distribute the load between them which will prevent them from becoming un duly worn or from fracturing when sub jected to hard usage. When the block 12 is reciprocated to move the jaws outwardly, the flat bottom face of the T-shaped extension on each of the actuating jaws will slide over the bottom of the T-shaped grooves in the block and also cause a positive actuation of the jaws in this direction;

Another advantage of the construction described is that the protector plate 20 and the boring bar bushing 17 effectually prevent any chips or any other foreign matter from entering the operating parts of the chuck. This will be clear from Fig. 3, from which it will be seen that the bushing 17 is rigidly secured to the protector plate 20, while the cylindrical block 12 is slidingly mounted upon the bushing. fore, the .slidingblock 12 is moved rearwardly, the bushing will not be displaced, and Wlll serve as a caslng to prevent any chips or other matter which enter through the hole in the protector; plates from cloging, the space between the front face of the blockandthe protector plate.

I claim:

1. In a chuck, a head comprising an annulanbody, a plurality of radially'disposed jaws slidingly mounted in said head, a. block having ,a linearly reciprocating movement in said head, said block and jaws having engaging parts for actuating said jaws upon movement of said 'block, a protector plate on thefront face of said head,.said block having an opening therein, and a bushing in said opening secured to said protector plate.

2. In a chuck, a head comprising an annular body, a plurality of radially disposed jaws slidably mounted in said head, a block having a linearly reciprocating movement in said head, said block and jawsv having engagingparts for actuating said jaws upon movement of sa d block-,- a protector plate on the-front face of said head, said protector plate and blockhaving axialfopenings, and

a bushing in the opening of the block for the purposeset forth.

In witness whereof, I subscribemy signature, in the presence of two witnesses.

EDVARD J. MCOLELLAN. lVitnesses RUBE FRANKEL, F. V. POWER.

Copies of this patent may be obtained for five cents each,iby addressing the Commissioner of Patents,

7 Washington, D. C.

When, there 

